WEPP: Soil erodibility experiments for rangeland and cropland soils

TLDR

WEPP is a process‑based simulation model that predicts soil erosion by water through rill and interrill detachment, contrasting with the empirical USLE, and relies on soil erodibility as a key determinant of erosion. The study aims to develop new soil erodibility parameters required by WEPP’s distinct predictive framework. Early in the project, the need for new erodibility parameters was recognized as a critical component for successful WEPP development.

Abstract

THE Water Erosion Prediction Project (WEPP) combines knowledge of soil erosion processes with other important processes in a simulation model to predict soil erosion by water ( 6, 9 ). WEPP models soil erosion as a process of rill and interrill detachment and transport ( 8 ). This is much different than the universal soil loss equation (USLE), in which the factors understood to affect soil erosion were quantified in an empirical technology ( 19 ). Because WEPP deals with soil erosion prediction in a different manner than the USLE, new soil erodibility parameters are required. This was identified early in the project as a critical component for the successful development of the WEPP technology ( 7 ). Soil erodibility in WEPP The susceptibility or resistance of a soil to detachment and transport usually is recognized as a major determinant of soil erosion for a particular site. Generally, soil erosion models, including the USLE, incorporate a soil's susceptibility to erosion as a single parameter, termed soil erodibility, in the portion of the model dealing with soil detachment and transport. Even such models as CREAMS ( 17 ), which are process-based, use the USLE soil erodibility values to compute needed erodibilities. Interrill erosion is the detachment and transport of soil particles by raindrops and …